1. Field of the Invention
The present invention generally relates to the art of forming a stack of crop material bales and, more particularly, is concerned with a bale wagon incorporating improved features for facilitating the formation of a block-type, tied or interlocked stack of bales thereon.
2. Description of the Prior Art
The present invention provides apparatus on a bale wagon for more consistently facilitating accurate selection of the desired sequence of tier patterns which will comprise the stack to be formed by the bale wagon. Such apparatus constitutes an alternative to, and under some conditions an improvement over, the load position sensing apparatus illustrated and described in U.S. Pat. No. 3,927,771 which issued Dec. 23, 1975 to Lee D. Butler and Edward J. Wynn and is assigned to the same assignee as the present invention.
The bale wagon disclosed in the aforesaid patent utilizes tier pattern sequence storage means in the form of a cam plate having a continuous peripheral edge on which is defined successive lobes which each correspond to, or represent, either a standard tier pattern or one of two different tie tier patterns into which bales that will form the stack are to be arranged. The lobes are arranged about the periphery of the cam plate in a sequence which corresponds to the desired sequence of the three basic tier patterns within the desired stack pattern. Such cam plate, constituting the memory of the bale wagon, is adjustably fixed on the upper end of a shaft which is rotatably mounted in a support assembly located below the rear end of the second table of the bale wagon.
Activation of the bale wagon memory is represented by rotation of the cam plate. Rotation of the cam plate successively disposes its peripheral lobes into contact with a cam follower. The cam follower in effect receives an instruction from the memory of the bale wagon, that being the lobe arrangement on the cam plate, and initiates transmission of that instruction to other operative parts of the bale wagon in order that a desired one of the tier patterns will be formed on the second table and delivered by the second table to the load bed of the bale wagon.
The lobes of the cam plate which respectively correspond to the three basic tier patterns are in the shape of arcs respectively struck by radii of different lengths from a common axis of revolution. Thus, each of the instructions received by the cam follower from the bale wagon memory is represented by the position of the cam follower along one of the three arcs forming the lobes and thus at one of three possible radial distances from the center of the cam plate.
It is important that the cam plate be accurately activated or rotated relative to the cam follower so that successive instructions (lobes) representing the desired sequence of tier patterns will be received by the cam follower. Under normal conditions, accurate sequential rotation of the cam plate with respect to the cam follower, such that the cam follower is successively positioned on the lobes arranged on the cam plate, may be achieved by accurate sensing of successive stack movements and positions along the load bed of the bale wagon during stack formation. Since, under normal conditions, the bales being stacked commonly have dimensions of 16 .times. 23 .times. 46 inches, the angular displacement between the lobes about the cam plate periphery may be designed to be proportionate to the various sequence of 16 and 23 inch dimensions of the stack tiers.
The features on the bale wagon disclosed in the aforesaid patent for sequentially rotating the cam plate in response to stack movements on the load bed are the rolling rack which supports the rear of the stack on the load bed, its hydraulic cylinder and the hydraulic circuitry associated therewith, a cable drum fixed on the rotatable shaft which also mounts the cam plate and motion transmitting means in the form of cables being routed along an endless path and interconnecting the rolling rack cylinder and the cable drum. Thus, as successive tiers are delivered by the second table to the front end of the load bed, the tier or tiers already standing upright on the load bed are moved toward the rear end of the load bed through a distance equal to the width of the flat (23 inches) or edge (16 inches) side of the bales, depending upon which of the sides of the bales is oriented in the horizontal plane, and, concurrently therewith, the rolling rack is moved through the same distance toward the rear end of the load bed. The hydraulic circuitry associated with the rolling rack cylinder insures that the rolling rack does not overrun. Thus, the rolling rack will only be moved through a distance equal to the bale width of the respective tier being delivered to the load bed and thereby the desired angular rotational displacement of the cam plate, being proportional to such bale width, will be transmitted to the cam plate via the cables and the cable drum.
From the above discussion, it will be realized that, under normal conditions when handling 16 .times. 23 .times. 46 bales, rotation of the cam plate will automatically, and can only, occur upon addition or delivery of a tier of bales to the load bed and thus its accurate rotative sequencing through the exact desired distance is guaranteed. Thus eliminated is the necessity of counting second table cycles in order to know when to form a tie tier pattern and also the possibibility of getting the cam plate out of its desired sequence should the empty second table be inadvertently cycled to its upper position.
However, due to variations in crop conditions some bales will expand and then be more than 16 inches in width. Further, some commercial balers make bales that are 161/2 to 17 inches wide. Thus, since the rotational displacement of the cam plate is proportional to the rearward displacement of the rolling rack and the rolling rack will be moved through a distance equal to the bale width of the respective tier being delivered to the load bed, when the bale width exceeds 16 inches the cam plate is successively over-rotated such that successive lobes on the cam plate progressively become increasingly more misaligned with the cam follower until an undesirable situation arises where the cam plate fails to provide the proper instruction to the cam follower with the result that the other operative parts of the bale wagon will not be correctly instructed as to which one of the tier patterns is to be formed next on the second table.
To summarize, while the use of the load position sensing apparatus disclosed and claimed in the aforesaid patent has proven to be a highly satisfactory method under normal conditions for accurately sequencing the cam plate, the above-noted undesirable situation has been encountered with such apparatus under the above-described deviations from normal conditions.